After nine weeks of negotiations, a £3 billion “powerhouse merger” between Carillion and Balfour Beatty has come to nought.

Barely a week since the two construction companies grandly proclaimed that a tie-up could create a “market leading business of considerable depth and scale”, talks have ended.

The collapse not only dashes hopes of creating a British “national champion” to rival global giants but also raises questions about the future of Balfour Beatty, a group that has been under pressure for some time.

Balfour has been involved in the M6 toll road, the London Aquatics Centre and the new Queen’s Terminal